U.S. Pat. No. 3,984,574, issued to Comollo, discloses an abhesive chewing gum base in which the non-tack properties were achieved by eliminating conventional chewing gum base ingredients which were found to contribute to chewing gum tackiness, and by substituting non-tacky ingredients in place of the conventional ingredients. Specifically, it was discovered that three classes of materials account for conventional chewing gum tackiness. These materials are elastomers, resins, and waxes.
Comollo eliminated natural and some synthetic elastomers from chewing gum base, and substituted in their place one or more non-tacky synthetic elastomers such as polyisobutylene, polyisoprene, isobutylene-isoprene copolymer and butadiene-styrene copolymer. Comollo also eliminated the tack-producing natural resins and modified natural resins and used instead relatively high amounts of hydrogenated or partially hydrogenated vegetable oils or animal fats. Finally, Comollo completely excluded waxes from the gum base, but included polyvinyl acetate, fatty acids, and mono and diglycerides of fatty acids. Comollo did not teach controlled release of sweeteners with abhesive chewing gums.
When wax-free gum bases are combined with water-soluble chewing gum ingredients, including sweeteners, bulking agents, binders, and the like, and flavoring agents, it has been determined that the chewing gums tend to release certain flavoring ingredients at accelerated rates. Also, a greater overall quantity of flavor is released from wax-free gums. This results not only in a stronger initial flavor impact, but also in a stronger flavor in later stages of chewing. This is taught in U.S. Pat. No. 5,286,501, issued Feb. 15, 1994. These rapid release effects are further magnified when the gum base is also free of elastomer plasticizers, because elastomer plasticizers, when present, tend to control and delay flavor release. Therefore, there is a need or desire to adjust the release of sweeteners present in abhesive wax-free chewing gum so that the sweetness release is compatible with the increased flavor release.